Rear firewall thickness

[SonicSW20]

Does anyone know how thick the rear firewall is? Need to drill through to mount an amp. Will be using M6 bolts. Just wondering if it's thick enough to be able to use a tap to create a thread, and how long the bolts will need to be.

[alanmr2turbo]

how heavy is your AMP to need bolts????? LOL. I fitting mine in the boot and just used 4 x self tapping screws

[SonicSW20]

Will weigh just under 6KG with the mounting board. I could use self tappers I guess.

[C35Rob]

The bulkhead between the cabin and engine bay? If so then it's double skinned with some PU sealant type stuff between the two skins, it is at the top at least anyway, as I found out when I mounted the eye bolts for my harness

[SonicSW20]

Yeah, that's the one. Won't be able to tap it then by the sounds of it!

[thomp1983]

You can't tap it but rivnuts should work nicely

[SonicSW20]

I don't have a rivnut tool, and I don't know anyone with one locally unfortunately.

[thomp1983]

You can drill straight through and nut and bolt it fine i did my old amp that way just allow for the carpet being surprisingly thick and needing a spare pair of hands

[SonicSW20]

I've just bought a rivet nut tool. The way the amp mounts is a bit odd, so I'm pitting an MDF board behind the carpet and mounting the amp to that.